EP3085939B1 - Piston for engine - Google Patents

Piston for engine Download PDF

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Publication number
EP3085939B1
EP3085939B1 EP16164969.4A EP16164969A EP3085939B1 EP 3085939 B1 EP3085939 B1 EP 3085939B1 EP 16164969 A EP16164969 A EP 16164969A EP 3085939 B1 EP3085939 B1 EP 3085939B1
Authority
EP
European Patent Office
Prior art keywords
resin coating
piston
coating film
moving direction
recess
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP16164969.4A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP3085939A1 (en
Inventor
Hiroki Oso
Hideyuki Koyama
Manabu Miyazaki
Hideyuki Goto
Takahito HAMASAKI
Takahiro Yamazaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Publication of EP3085939A1 publication Critical patent/EP3085939A1/en
Application granted granted Critical
Publication of EP3085939B1 publication Critical patent/EP3085939B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/10—Pistons  having surface coverings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/0084—Pistons  the pistons being constructed from specific materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J1/00—Pistons; Trunk pistons; Plungers
    • F16J1/02—Bearing surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J1/00—Pistons; Trunk pistons; Plungers
    • F16J1/08—Constructional features providing for lubrication
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/02—Pistons  having means for accommodating or controlling heat expansion
    • F02F3/027—Pistons  having means for accommodating or controlling heat expansion the skirt wall having cavities
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2253/00—Other material characteristics; Treatment of material
    • F05C2253/12—Coating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2253/00—Other material characteristics; Treatment of material
    • F05C2253/20—Resin

Definitions

  • the present invention relates to a piston for an engine, in particular, to a piston for an engine capable of improving supply of engine oil to a recess.
  • a piston for an engine having a resin coating film 102 and a recess 103 on a surface of a skirt part 101 is known (for example, see Japanese Patent No. 4749399 ( FIG. 1 )).
  • a profile of the skirt part 101 is optimized by the resin coating film 102, and there are obtained advantages of reducing slapping noise of the piston and friction of the skirt part 101 by engine oil stored in the recess 103.
  • the recess 103 since the plurality of recesses 103 are discretely arranged in spots on the single resin coating film 102, the recess 103 is surrounded by the resin coating film 102 and therefore it is difficult to supply the engine oil to the recess 103. Thus, a sufficient amount of the engine oil is not held in the recess 103 and therefore the friction reducing function of the engine oil for the skirt part 101 is insufficient.
  • An object of the present invention is to provide a piston for an engine capable of improving supply of engine oil to a recess based on further study of a piston on which a resin coating film is formed.
  • the concave shape of the end part 2A of the another resin coating film 2 in the piston moving direction is set to a V-shape.
  • a V-shape angle is set to a range of 120 degrees ⁇ 20 degrees.
  • the concave shape of the end part 2A of the another resin coating film 2 in the piston moving direction is set to a curved shape.
  • a length of the resin coating film 2 in the piston moving direction is set to be longer than a length of the resin coating film 2 in the piston circumference direction.
  • an engine oil holding area can be provided over a wide area on the skirt part. Since the overall resin coating film is arranged in a plurality of discrete spots on the surface of the skirt part and the mesh-like groove is formed by a recess defined by the discrete resin coating films adjacent to each other and the surface of the skirt part between the resin coating films adjacent to each other, the engine oil holding area can be provided over the wide area on the skirt part.
  • the end part of another resin coating film in the piston moving direction is formed in a concave shape when seen in a piston radius direction, a lubricant which has moved along the recess by inertia in accordance with a piston movement collides against the concave end part of the another resin coating film. Due to an angle of the concave shape, the lubricant does not move away in the circumference direction, but tends to return to the original recess by a bounce back movement.
  • the piston for the engine capable of improving supply of the engine oil to the recess can be provided.
  • Examples of the concave shape of the end part of the another resin coating film may include a V-shape according to the second aspect, and a curved shape according to the fourth aspect. Further, it is preferable to set a V-shape angle to a range of 120 degrees ⁇ 20 degrees according to the third aspect because the lubricant holding property is further improved. Further, it is preferable to set a shape of the resin coating film according to the fifth aspect such that a length of the resin coating film in the piston moving direction is longer than a length of the resin coating film in the piston circumference direction.
  • a vertical type diesel engine and a piston thereof are formed such that a cylinder head 15 is assembled above a cylinder 14, a piston 12 is fitted into the cylinder 14, and a crank shaft 17 is interlockingly connected to the piston 12 via a con-rod 16.
  • An intake valve 18, an exhaust valve 19, and a fuel injector 20 are mounted to the cylinder head 15.
  • the overall resin coating film is formed by a plurality of resin coating films 2 that are arranged in a plurality of discrete spots on the surface of the skirt part 1, and a mesh-like groove 4 is formed by a recess 3 defined by the resin coating films 2, 2 adjacent to each other and the surface of the skirt part 1 between the resin coating films 2, 2 adjacent to each other.
  • the mesh-like groove 4 is formed between the resin coating films 2, 2 adjacent to each other and a bottom of the mesh-like groove 4 is formed by a metal surface of the skirt part 1 which is not covered with the resin coating film 2.
  • the plurality of resin coating films 2, each of which comprises a discrete spot, may be considered to define, together, an overall resin coating film.
  • the resin coating film 2 and the recess 3 are formed at a thrust side 12a and an anti-thrust side 12b of the piston 12.
  • the thrust side 12a refers to a side where the piston 12 is pressed against the cylinder 14 by a combustion pressure when the piston 12 is moved downward in a combustion process
  • the anti-thrust side 12b refers to a side opposite to the thrust side 12a.
  • a body of the piston 12 is made of a metal material such as cast iron or aluminum alloy.
  • the resin coating film 2 is made of a resin material such as polyamide resin, epoxy resin, phenol resin, silicon resin, or polyimide resin.
  • An inorganic solid lubricant such as transition metal oxide or graphite is contained in the resin coating film 2.
  • the resin coating film 2 is formed in a substantially rectangular shape in which a length of the resin coating film 2 in a piston moving direction 6 is longer than a length of the resin coating film 2 in a piston circumference direction 8.
  • both end parts 2A, 2A of the resin coating film 2 in its longitudinal direction are formed in a concave shape, in particular, in a V-shape having edge surfaces 2a, 2a.
  • the resin coating film 2 and the recess 3 are provided adjacent to each other in the piston moving direction 6.
  • the recess 3 formed on the skirt part between the resin coating films 2, 2 adjacent to each other in the piston circumference direction 8 of the skirt part 1 is set to be adjacent to another resin coating film 2 in the piston moving direction 6, and end parts 2A of the another resin coating film 2 in the piston moving direction 6 are formed in a concave shape when seen in the piston radius direction.
  • the resin coating film 2 has a pair of vertical sides 2B, 2B along the piston moving direction 6, and the both end parts 2A, 2A (short sides). Each of the end parts 2A is formed in a V-shape by a pair of edge surfaces 2a, 2a.
  • the resin coating film 2 is formed in a substantially rectangular shape (laid hand drum like shape) in which the vertical side 2B is apparently longer than the width of the resin coating film 2.
  • a ratio of a length of the resin coating film 2 in the piston moving direction 6, a length of the resin coating film 2 in the piston circumference direction 8, the minimum distance between the resin coating films 2, 2 adjacent to each other in the piston moving direction 6, and a distance between the resin coating films 2, 2 adjacent to each other in the piston circumference direction 8 (a width of a groove portion 7) is set to 40 : 12 : 6 : 5, however the ratio is not limited to this.
  • a resin coating film row 5 formed with a plurality of the resin coating films 2 that are arranged at a predetermined interval in the piston circumference direction 8 of the skirt part 1.
  • a plurality of the resin coating film rows 5 are arranged in a zigzag manner in the piston moving direction 6 such that each of the resin coating film rows 5 is shifted by a half pitch in the piston circumference direction 8 with respect to the adjacent resin coating film row 5.
  • both end openings 7a, 7b in the piston moving direction 6 of the groove portion 7 (recess 3) formed between the resin coating films 2, 2 adjacent to each other in the resin coating film row 5 are provided to face the resin coating film 2 in the adjacent resin coating film row 5 in a piston moving direction 6, in particular, to face the center part of the resin coating film 2 in the piston circumference direction 8.
  • a narrow angle ⁇ formed by right and left edge surfaces 2a, 2a of the end part 2A of the resin coating film 2 is set to an angle of 120 degrees (alternatively, a range of 120 degrees ⁇ 20 degrees).
  • an effect is obtained by setting the angle ⁇ to a range of 60 degrees ⁇ ⁇ ⁇ 180 degrees, but a better effect may be obtained by setting the angle ⁇ to a range of "120 degrees ⁇ 20 degrees".
  • a lubricant which moves in the recess 3 or the groove portion 7 formed between the resin coating films 2, 2 adjacent to each other in the piston circumference direction 8 in accordance with the movement (up and down) of the piston 12, flows out of the opening 7a, collides against the end part 2A of the adjacent resin coating film 2 in the piston moving direction 6 to be received, and then the lubricant is bounced back by the pair of the edge surfaces 2a, 2a.
  • a recess which is formed by the end parts 2A of the resin coating films 2 adjacent to each other and which extends in the piston circumference direction 8 in a zigzag manner, forms an oil storing groove 9 having an excellent lubricant holding property.
  • the adjacent resin coating film in the piston moving direction preferably overlaps the end opening of the recess. It may completely overlap the end opening.
  • the bounced-back lubricant collides with the end part 2A of the resin coating film 2 forming the groove portion 7 and is further bounced back, or flows back to the original groove portion 7, the lubricant holding property is improved. Further, the bounced-back lubricant tends to move onto the resin coating film 2 adjacent to the groove portion 7, and therefore a positive pressure is generated between the cylinder 14 and the piston 12. The positive pressure separates a sliding surface of the piston 12 from a cylinder wall and reduces a friction, and therefore fuel efficiency can be improved.
  • a vertical direction (piston moving direction 6) passage of the lubricant can be formed by separately applying a texturing process to each area on a surface of the skirt part 1, and the lubricant can be effectively supplied to each part of the piston 12. Since the resin coating film rows 5, 5 adjacent to each other in the piston moving direction 6 are arranged in a zigzag manner by shifting the resin coating film rows 5 with respect to each other in the piston circumference direction 8, the lubricant can be efficiently supplied to the recess 3 by using a reciprocating movement of the piston 12.
  • a length of a vertical side 2B of a resin coating film 2 is substantially half of a length of the vertical side 2B of the resin coating film 2 (see FIG. 2A and 2B ) according to the first embodiment.
  • a concave shape of an end part 2A of a resin coating film 2 in a piston moving direction 6 is set to a curved shape, and the end part 2A has a curved edge surface 10.
  • edge parts 11, which are formed in a convex curved shape when seen in a piston radius direction, are provided at both ends of the end part 2A in a width direction of the resin coating film 2.
  • a concave shape of an end part 2A of a resin coating film 2 in a piston moving direction 6 may be formed by three surfaces including a bottom surface 13, and left and right inclined surfaces 21, 21.
  • a concave shape of an end part 2A of a resin coating film 2 in a piston moving direction 6 may be formed by a V-shape bottom surface 22 and right and left convex parts 23, 23.
  • a concave shape of an end part 2A of a resin coating film 2 in a piston moving direction 6 may include a single concave curved surface 24.
  • the concave curved surface 24 may have various shapes such as a circular shape and an ellipse shape.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
EP16164969.4A 2015-04-22 2016-04-12 Piston for engine Active EP3085939B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2015087827A JP6401104B2 (ja) 2015-04-22 2015-04-22 エンジンのピストン

Publications (2)

Publication Number Publication Date
EP3085939A1 EP3085939A1 (en) 2016-10-26
EP3085939B1 true EP3085939B1 (en) 2024-03-06

Family

ID=55755378

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16164969.4A Active EP3085939B1 (en) 2015-04-22 2016-04-12 Piston for engine

Country Status (4)

Country Link
US (1) US10018147B2 (ja)
EP (1) EP3085939B1 (ja)
JP (1) JP6401104B2 (ja)
CN (1) CN106065826B (ja)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6443759B2 (ja) * 2015-05-25 2018-12-26 スズキ株式会社 内燃機関のピストン
JP6587978B2 (ja) * 2016-06-01 2019-10-09 株式会社クボタ エンジンのピストン
FR3094044B1 (fr) * 2019-03-21 2022-10-14 Psa Automobiles Sa Piston de moteur a combustion interne
DE102019219445A1 (de) * 2019-12-12 2021-06-17 Federal-Mogul Nürnberg GmbH Kolben und Verfahren zur Herstellung desselben
JP2021102928A (ja) * 2019-12-24 2021-07-15 トヨタ自動車株式会社 ピストン

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2529001Y2 (ja) * 1990-09-27 1997-03-12 アイシン精機株式会社 内燃機関用ピストン
US6675761B2 (en) * 2002-01-30 2004-01-13 Caterpillar Inc Ring band for a piston
DE10244511A1 (de) * 2002-09-25 2004-04-15 Mahle Gmbh Mehrteiliger gekühlter Kolben für einen Verbrennungsmotor
JP2004137955A (ja) * 2002-10-17 2004-05-13 Ntn Corp 内燃機関用ピストン
US7171936B2 (en) * 2003-10-23 2007-02-06 Mahle Technology, Inc. Piston having a patterned coating and method of applying same
JP2005320934A (ja) * 2004-05-11 2005-11-17 Toyo Drilube Co Ltd 往復運動部材
US7406941B2 (en) * 2004-07-21 2008-08-05 Federal - Mogul World Wide, Inc. One piece cast steel monobloc piston
US20060086325A1 (en) * 2004-10-25 2006-04-27 Ipd, Inc. Two piece cast ferrous crown piston for internal combustion engine
JP4749399B2 (ja) 2007-08-24 2011-08-17 本田技研工業株式会社 内燃機関のピストン
JP5720481B2 (ja) * 2011-08-09 2015-05-20 スズキ株式会社 内燃機関用ピストン
JP6066836B2 (ja) * 2013-05-31 2017-01-25 株式会社クボタ エンジンのピストン

Also Published As

Publication number Publication date
JP6401104B2 (ja) 2018-10-03
CN106065826B (zh) 2020-04-03
CN106065826A (zh) 2016-11-02
JP2016205236A (ja) 2016-12-08
US10018147B2 (en) 2018-07-10
US20160312739A1 (en) 2016-10-27
EP3085939A1 (en) 2016-10-26

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